/**
 * ***************************************************************************** Copyright (c) 2000,
 * 2005 IBM Corporation and others. All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0 which accompanies this
 * distribution, and is available at http://www.eclipse.org/legal/epl-v10.html
 *
 * <p>Contributors: IBM Corporation - initial API and implementation
 * *****************************************************************************
 */
package org.tigris.subversion.subclipse.ui.comments;

import org.eclipse.jface.dialogs.Dialog;
import org.eclipse.jface.dialogs.IDialogConstants;
import org.eclipse.jface.dialogs.IInputValidator;
import org.eclipse.swt.SWT;
import org.eclipse.swt.events.ModifyEvent;
import org.eclipse.swt.events.ModifyListener;
import org.eclipse.swt.layout.GridData;
import org.eclipse.swt.widgets.Button;
import org.eclipse.swt.widgets.Composite;
import org.eclipse.swt.widgets.Control;
import org.eclipse.swt.widgets.Label;
import org.eclipse.swt.widgets.Shell;
import org.eclipse.swt.widgets.Text;

/**
 * A simple input dialog for soliciting an input string from the user.
 *
 * <p>This concrete dialog class can be instantiated as is, or further subclassed as required.
 */
public class CommentTemplateEditDialog extends Dialog {
  /** The title of the dialog. */
  private String title;

  /** The message to display, or <code>null</code> if none. */
  private String message;

  /** The input value; the empty string by default. */
  private String value = ""; // $NON-NLS-1$

  /** The input validator, or <code>null</code> if none. */
  private IInputValidator validator;

  /** Ok button widget. */
  private Button okButton;

  /** Input text widget. */
  private Text text;

  /** Error message label widget. */
  private Text errorMessageText;

  /**
   * Creates an input dialog with OK and Cancel buttons. Note that the dialog will have no visual
   * representation (no widgets) until it is told to open.
   *
   * <p>Note that the <code>open</code> method blocks for input dialogs.
   *
   * @param parentShell the parent shell, or <code>null</code> to create a top-level shell
   * @param dialogTitle the dialog title, or <code>null</code> if none
   * @param dialogMessage the dialog message, or <code>null</code> if none
   * @param initialValue the initial input value, or <code>null</code> if none (equivalent to the
   *     empty string)
   * @param validator an input validator, or <code>null</code> if none
   */
  public CommentTemplateEditDialog(
      Shell parentShell,
      String dialogTitle,
      String dialogMessage,
      String initialValue,
      IInputValidator validator) {
    super(parentShell);
    this.title = dialogTitle;
    message = dialogMessage;
    if (initialValue == null) value = ""; // $NON-NLS-1$
    else value = initialValue;
    this.validator = validator;
  }

  /*
   * (non-Javadoc) Method declared on Dialog.
   */
  protected void buttonPressed(int buttonId) {
    if (buttonId == IDialogConstants.OK_ID) {
      value = text.getText();
    } else {
      value = null;
    }
    super.buttonPressed(buttonId);
  }

  /*
   * (non-Javadoc)
   *
   * @see org.eclipse.jface.window.Window#configureShell(org.eclipse.swt.widgets.Shell)
   */
  protected void configureShell(Shell shell) {
    super.configureShell(shell);
    if (title != null) shell.setText(title);
  }

  /*
   * (non-Javadoc)
   *
   * @see org.eclipse.jface.dialogs.Dialog#createButtonsForButtonBar(org.eclipse.swt.widgets.Composite)
   */
  protected void createButtonsForButtonBar(Composite parent) {
    // create OK and Cancel buttons by default
    okButton = createButton(parent, IDialogConstants.OK_ID, IDialogConstants.OK_LABEL, true);
    createButton(parent, IDialogConstants.CANCEL_ID, IDialogConstants.CANCEL_LABEL, false);
    // do this here because setting the text will set enablement on the ok
    // button
    text.setFocus();
    if (value != null) {
      text.setText(value);
      text.selectAll();
    }
  }

  /*
   * (non-Javadoc) Method declared on Dialog.
   */
  protected Control createDialogArea(Composite parent) {
    // create composite
    Composite composite = (Composite) super.createDialogArea(parent);
    // create message
    if (message != null) {
      Label label = new Label(composite, SWT.WRAP);
      label.setText(message);
      GridData data =
          new GridData(
              GridData.GRAB_HORIZONTAL
                  | GridData.GRAB_VERTICAL
                  | GridData.HORIZONTAL_ALIGN_FILL
                  | GridData.VERTICAL_ALIGN_CENTER);
      data.widthHint = convertHorizontalDLUsToPixels(IDialogConstants.MINIMUM_MESSAGE_AREA_WIDTH);
      label.setLayoutData(data);
      label.setFont(parent.getFont());
    }
    text = new Text(composite, SWT.MULTI | SWT.BORDER);
    GridData gd = new GridData(GridData.GRAB_HORIZONTAL | GridData.HORIZONTAL_ALIGN_FILL);
    gd.heightHint = convertHeightInCharsToPixels(5);
    text.setLayoutData(gd);
    text.addModifyListener(
        new ModifyListener() {
          public void modifyText(ModifyEvent e) {
            validateInput();
          }
        });
    errorMessageText = new Text(composite, SWT.READ_ONLY);
    errorMessageText.setLayoutData(
        new GridData(GridData.GRAB_HORIZONTAL | GridData.HORIZONTAL_ALIGN_FILL));
    errorMessageText.setBackground(
        errorMessageText.getDisplay().getSystemColor(SWT.COLOR_WIDGET_BACKGROUND));

    applyDialogFont(composite);
    return composite;
  }

  /**
   * Returns the error message label.
   *
   * @return the error message label
   * @deprecated use setErrorMessage(String) instead
   */
  protected Label getErrorMessageLabel() {
    return null;
  }

  /**
   * Returns the ok button.
   *
   * @return the ok button
   */
  protected Button getOkButton() {
    return okButton;
  }

  /**
   * Returns the text area.
   *
   * @return the text area
   */
  protected Text getText() {
    return text;
  }

  /**
   * Returns the validator.
   *
   * @return the validator
   */
  protected IInputValidator getValidator() {
    return validator;
  }

  /**
   * Returns the string typed into this input dialog.
   *
   * @return the input string
   */
  public String getValue() {
    return value;
  }

  /**
   * Validates the input.
   *
   * <p>The default implementation of this framework method delegates the request to the supplied
   * input validator object; if it finds the input invalid, the error message is displayed in the
   * dialog's message line. This hook method is called whenever the text changes in the input field.
   */
  protected void validateInput() {
    String errorMessage = null;
    if (validator != null) {
      errorMessage = validator.isValid(text.getText());
    }
    // Bug 16256: important not to treat "" (blank error) the same as null
    // (no error)
    setErrorMessage(errorMessage);
  }

  /**
   * Sets or clears the error message. If not <code>null</code>, the OK button is disabled.
   *
   * @param errorMessage the error message, or <code>null</code> to clear
   * @since 3.0
   */
  public void setErrorMessage(String errorMessage) {
    errorMessageText.setText(errorMessage == null ? "" : errorMessage); // $NON-NLS-1$
    okButton.setEnabled(errorMessage == null);
    errorMessageText.getParent().update();
  }
}
